Supervisory control and data acquisition protocol converter

Abstract

A supervisory control and data acquisition protocol converter having encoded meter register input ports which are able to interrogate, read, and retain data stored in viscous fluid or gas meter registers which communicate with the Automatic Meter Reading (AMR) protocols and convert that data upon request to an industrial monitoring and control system protocol such as MODBUS®, DF1, EtherNet / IP™, or ADAM 4000. The present art further provides serial RS-232C and RS-485, and Ethernet ports whereby said data may be transmitted and / or the apparatus may be setup according to user defined specifications. The present art apparatus also provides industrial standard pulse (0-5 volts) and current (4-20 milliamps) inputs. The present art further provides a user configurable display which may display any or only a portion of the aforesaid data along with other user desired data. The apparatus further serves a web page over the Ethernet port with the aforesaid data populating a table.

Description

[0001]This application claims priority of U.S. Provisional Patent Application No. 61 / 069,855, filed Mar. 18, 2008, entitled Supervisory Control and Data Acquisition Protocol Converter.BACKGROUND OF THE INVENTION[0002]The art of the present invention relates to electronic protocol converters in general and more particularly to an electronic protocol converter which allows industrial Supervisory Control and Data Acquisition (hereafter referred to as “SCADA”) Systems (also industrial monitoring and control systems) to utilize standard industrial protocols to interrogate viscous fluid or gas meter registers which communicate with Automatic Meter Reading (hereafter referred to as “AMR”) protocols. The present art methods of implementation and associated apparatus provide an interface with and allow interrogation of the encoded meter registers which are typically utilized by municipal utilities in residential and commercial applications. (i.e. water utility companies, gas utility companie...

AI Technical Summary

Benefits of technology

[0026]FIG. 4 shows an external view of a preferred embodiment of the present art apparatus. The apparatus bridges the communication gap between encoded meter registers and industrial control systems. The apparatus is understood within the arts as a protocol translator which enables industrial control systems to interrogate encoded registers in their native industrial protocols. The preferred embodiment communicates precise totalization and accurate flow rate information. That is, the apparatus formats totalization data to perform a first derivative with respect to time of the meter totalization. For the preferred embodiment, the derivative is performed or placed in a format as a finite-difference of the meter totalization with respect to time (delta volume per delta time). That is:

[0029]For the preferred embodiment, the apparatus is powered by an external DC voltage source, preferably between 9 and 36V. Alternative embodiments may utilize AC, DC, or combined power source of a plurality of values. Also in the preferred embodiment, a rectifier diode protects the circuit from accidental reverse hookup of the power supply and a fuse and nine (9) zener diodes protect the circuit against transient over-voltages.

Problems solved by technology

Due to the significant communication barrier, SCADA integrators have not utilized encoded registers for their systems.

Unfortunately, the electronic communication protocol which the first category residential and commercial meters utilize has heretofore been obscure in publication, difficult to reverse engineer, or non-standardized between various manufactures.

Totalization may also be obtained by performing an integral computation of the flow signal with respect to time, but a totalization error of some tangible magnitude would normally occur due to digital integration noise.

Within the industrial monitoring and control arts, prior art meter reading technology that depends upon pulse-output and current-output registers faces significant and inherent challenges in obtaining accurate meter totalizations, especially over long periods of time.

However, in practice, problems often arise.

For example, if the PLC / RTU is shut off for any reason while water is flowing through the meter (eg. power outages, equipment failure, broken cable / connector), the PLC / RTU will not be able to count those pulses.

Furthermore, some PLC / RTU equipment does not store the running totalization in non-volatile memory, so upon re-start from a shutdown, the PLC / RTU will erroneously begin its count from zero.

The prior art is further limited in its ability to differentiate the fluid flow direction.

Occasionally, some pulse-output registers emit noise, which can be interpreted by the PLC / RTU as valid pulses, and therefore the accumulated total in the PLC / RTU will be erroneously high.

Over long periods of time, one or more of the aforementioned prior art issues can cause the totalization obtained from the pulse-counting and flow-integrating methods to differ so greatly from the true reading on the internal mechanical register of the meter that it becomes almost unusable.

This increases the maintenance, environmental, and other overall costs of the Industrial Control System.

None of the aforesaid billing and / or accounting applications utilize, convert to, or format the AMR meter data into generally accepted industrial protocols as does the present art nor do they allow communication with said industrial protocols.

Although industrial control and monitoring systems could also benefit from the superior accuracy of encoded registers, prior to the present art, no devices have existed that were capable of performing the necessary protocol translation between encoded registers and the industrial control and monitoring systems.

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